Many internal combustion engines include a turbocharger to achieve improvements in consumption, emissions, and/or power. The exhaust gas from the engine flows through a turbine, which drives a compressor and thus forces more air into the combustion chamber. The turbocharger is usually arranged in direct proximity to the engine, downstream of the exhaust manifold. The turbine blades, in particular, as well as the turbine housing, are exposed to particularly high temperatures by the hot exhaust gas flowing through. Two common methods are used for ensuring the durability of the turbocharger over the service life.
In the first method, the turbine housing is produced from high-strength high-temperature steel and the housing is cooled by selective air routing in the engine compartment. The waste heat from the turbocharger is dissipated into the environment.
In the second method, the turbine housing is produced from aluminum and is cooled selectively by means of a water cooling jacket. The cooling liquid is diverted from the cooling circuit of the engine and the heated coolant is fed back into the cooling circuit after flowing through the turbine housing. The waste heat from the turbocharger thus contributes to faster heating of the coolant of the engine after cold starting.